Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

Thank goodness it's Friday! The broad-based S&P 500 (SNPINDEX:^GSPC) certainly didn't have a miserable week on a percentage basis, but it has finished marginally lower in four of the past five trading sessions.

Earnings were the talk of the town this week, with earnings beats still handily outpacing Wall Street's estimates for a majority of stocks. The concern remains that top-line revenue beats have come in at a much lower clip than EPS beats, signaling to investors that cost-cutting, rather than business expansion, is what's causing earnings to grow. Efficiency is a good thing; don't get me wrong. But, investors would much prefer to see businesses taking on additional employees, innovating, and making acquisitions, than laying off employees and reducing administrative salaries to boost profits as sales growth stagnates.

By the end of the day the S&P 500 had finished lower by 6.06 points (-0.36%) to close at 1,691.42 – a little more than 1% below its all-time closing high, set last week.

Working its way to be among the S&P 500's top gainers for a second-straight session is iron ore miner Cliffs Natural Resources (NYSE:CLF), which added 10.6% today on top of yesterday's 8.9% gain. The reason for the impressive move has to do with data out of China that signaled industrial production grew by 9.7% in July, which marks its fastest pace since February. Cliffs is counting on robust infrastructure growth in China to fuel demand for its iron ore – especially with iron ore prices falling considerably from their year-to-date highs set back in February. Cliffs' quarterly results certainly shocked Wall Street in that iron ore demand was better-than-expected, which could bode well for future gains.

Partially riding the coattails of the same news story is coal miner Peabody Energy (NYSE:BTU), which advanced 7.8% on the day. The thesis here is that if industrial production in China is surging once again, the energy needs of the country are only bound to increase, meaning potentially more demand for thermal coal. Also, if the thesis for strong infrastructure growth remains intact, then metallurgical coal demand, which is used to strengthen steel, may also rise. The other half of the equation to today's rally comes from Moody's, which raised its outlook on the coal industry to stable, from negative. Specifically, Moody's notes that, while it expects business conditions to remain weak, it doesn't see them weakening further over the next 12 to 18 months. I remain a big fan of the coal industry, and feel that some of these names could be ripe for the picking.

Finally, audio equipment maker Harman International (NYSE:HAR), like Cliffs, once again worked its way back into the mix of biggest gainers, rising 6% today after gaining by double-digits yesterday. Unlike Cliffs or Peabody, Harman's move was entirely a carryover from the guidance its management team released yesterday, which called for EBITDA margins to improve from 10.5% of revenue in 2014, to as high as 13% in 2016. With Harman announcing a 100% increase to its dividend earlier this week, it has to be back on the radar of value-seeking investors.